-
Are any of the rando bags really that waterproof though... they all have stitched seams and huge top opening... I suppose you could go all out and have a floating welded roll-top inner, but that'd add weight, cost and compromise ease of access.
With any bike-luggage solution you should always be stashing stuff in dry bags if you don't want it getting wet, whatever the manufacturer claims.
-
My GB was surprisingly waterproof, and last some several rain during some of the audax ride.
That's mainly because they used the old method of making it waterproof, as the fabric expand when wet preventing it from going through.
The Swifts handlebar bag got quite damp on the inside despite being lined with those waterproof material.
Swift Industries is defintely not that waterproof.